It is certainly very sad to see the continuing divisions around the world due to the proposed signing of an agreement with Rome, which now seems unlikely... though we shall see. However, regarding Fr Cardozo, he is very much an SSPX priest and was ordained by Mons Lefebvre and he remains very attached to him and what Mons. created. He had a run-in with Fr Trejo the superior, due to some irregularities he uncovered. As had happened with other priests in other parts, he was not listened to by Mons.F., though he had the support at the time of Mons. T de M. The faithful in Chihuahua were also unhappy, and have continued to support Fr Cardozo.
He was eventually moved by Mons. F. to a priory in Brazil, but then spoke out against the agreement, as have Frs. Chazal, Pfeiffer, Koller, Mons. T de Mallerais, etc., and was told to leave and chose to go to the Monastery of Santa Cruz. Somebody said somewhere that the Monastery would be expelled from the SSPX, but it is autonomous, so that's wrong. But, they are also totally against an agreement and follow Mons. Lefebvre; in fact he congratulated the Prior for not signing with Rome years back when Fr Gérard did so.
From what I have heard personally, Fr Cardozo is angry, and I know that quite a number of faithful who already knew Father when he was in Mexico, did attend a Mass in a private house. There is absolutely no right for Fr Trejo to forbid the faithful from attending a Mass by a priest of the SSPX, even if he being forbidden to use an SSPX church or chapel, as Neil Obstat says 'the faithful are not members and can attend a Mass even by an independent priest. The Society has used independent priests on occasion when it was convenient.
I also know that all the priests I know in the UK are united against an agreement with Rome at this time.
We must continue to pray that unity will be restored, though this may well be very difficult due to strong language on both sides, ie for and against an agreement. The great problem arose because of SECRECY on the part of the Sup. Gen.